Would you speak up to a narcissist ex friend?

My friend of 27 years keeps messaging me every so often to come visit her but I do not reply. I stopped contact with her 4 years ago due to her lying to me twice and also putting my sister down over her medical condition..telling my sister to just "GET OUT MORE" when she has unbearable pain. Also told her not to "feel sorry for herself" 😵
I just do not reply to her messages because if you tell her she defends herself and thinks she does NO wrong..ever. Would you eventually say "I am no longer friends?? " Or just let it go until she sends another message? Only ONCE i spoke up to her in 27 years and she wrote 3 paragraphs defending her rude behavior then said *I* was "punishing" her..just for saying ONE thing I thought. 😶